You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
- Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
+ Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA. */
#include "bfd.h"
#include "sysdep.h"
#include "bfdlink.h"
#include "libbfd.h"
#include "elf-bfd.h"
+#include "elf-vxworks.h"
/* 386 uses REL relocations instead of RELA. */
#define USE_REL 1
#define PLT_ENTRY_SIZE 16
/* The first entry in an absolute procedure linkage table looks like
- this. See the SVR4 ABI i386 supplement to see how this works. */
+ this. See the SVR4 ABI i386 supplement to see how this works.
+ Will be padded to PLT_ENTRY_SIZE with htab->plt0_pad_byte. */
-static const bfd_byte elf_i386_plt0_entry[PLT_ENTRY_SIZE] =
+static const bfd_byte elf_i386_plt0_entry[12] =
{
0xff, 0x35, /* pushl contents of address */
0, 0, 0, 0, /* replaced with address of .got + 4. */
0xff, 0x25, /* jmp indirect */
- 0, 0, 0, 0, /* replaced with address of .got + 8. */
- 0, 0, 0, 0 /* pad out to 16 bytes. */
+ 0, 0, 0, 0 /* replaced with address of .got + 8. */
};
/* Subsequent entries in an absolute procedure linkage table look like
0, 0, 0, 0 /* replaced with offset to start of .plt. */
};
-/* The first entry in a PIC procedure linkage table look like this. */
+/* The first entry in a PIC procedure linkage table look like this.
+ Will be padded to PLT_ENTRY_SIZE with htab->plt0_pad_byte. */
-static const bfd_byte elf_i386_pic_plt0_entry[PLT_ENTRY_SIZE] =
+static const bfd_byte elf_i386_pic_plt0_entry[12] =
{
0xff, 0xb3, 4, 0, 0, 0, /* pushl 4(%ebx) */
- 0xff, 0xa3, 8, 0, 0, 0, /* jmp *8(%ebx) */
- 0, 0, 0, 0 /* pad out to 16 bytes. */
+ 0xff, 0xa3, 8, 0, 0, 0 /* jmp *8(%ebx) */
};
/* Subsequent entries in a PIC procedure linkage table look like this. */
0, 0, 0, 0 /* replaced with offset to start of .plt. */
};
+/* On VxWorks, the .rel.plt.unloaded section has absolute relocations
+ for the PLTResolve stub and then for each PLT entry. */
+#define PLTRESOLVE_RELOCS_SHLIB 0
+#define PLTRESOLVE_RELOCS 2
+#define PLT_NON_JUMP_SLOT_RELOCS 2
+
/* The i386 linker needs to keep track of the number of relocs that it
decides to copy as dynamic relocs in check_relocs for each symbol.
This is so that it can later discard them if they are found to be
asection *srelplt;
asection *sdynbss;
asection *srelbss;
+
+ /* The (unloaded but important) .rel.plt.unloaded section on VxWorks. */
+ asection *srelplt2;
+
+ /* Short-cuts to frequently used symbols for VxWorks targets. */
+ struct elf_link_hash_entry *hgot, *hplt;
+
+ /* True if the target system is VxWorks. */
+ int is_vxworks;
+ /* Value used to fill the last word of the first plt entry. */
+ bfd_byte plt0_pad_byte;
+
union {
bfd_signed_vma refcount;
bfd_vma offset;
ret->srelbss = NULL;
ret->tls_ldm_got.refcount = 0;
ret->sym_sec.abfd = NULL;
+ ret->is_vxworks = 0;
+ ret->srelplt2 = NULL;
+ ret->hgot = NULL;
+ ret->hplt = NULL;
+ ret->plt0_pad_byte = 0;
return &ret->elf.root;
}
if (!htab->sgot || !htab->sgotplt)
abort ();
- htab->srelgot = bfd_make_section (dynobj, ".rel.got");
+ htab->srelgot = bfd_make_section_with_flags (dynobj, ".rel.got",
+ (SEC_ALLOC | SEC_LOAD
+ | SEC_HAS_CONTENTS
+ | SEC_IN_MEMORY
+ | SEC_LINKER_CREATED
+ | SEC_READONLY));
if (htab->srelgot == NULL
- || ! bfd_set_section_flags (dynobj, htab->srelgot,
- (SEC_ALLOC | SEC_LOAD | SEC_HAS_CONTENTS
- | SEC_IN_MEMORY | SEC_LINKER_CREATED
- | SEC_READONLY))
|| ! bfd_set_section_alignment (dynobj, htab->srelgot, 2))
return FALSE;
return TRUE;
elf_i386_create_dynamic_sections (bfd *dynobj, struct bfd_link_info *info)
{
struct elf_i386_link_hash_table *htab;
+ asection * s;
+ int flags;
+ const struct elf_backend_data *bed = get_elf_backend_data (dynobj);
htab = elf_i386_hash_table (info);
if (!htab->sgot && !create_got_section (dynobj, info))
|| (!info->shared && !htab->srelbss))
abort ();
+ if (htab->is_vxworks && !info->shared)
+ {
+ s = bfd_make_section (dynobj, ".rel.plt.unloaded");
+ flags = (SEC_HAS_CONTENTS | SEC_IN_MEMORY | SEC_READONLY
+ | SEC_LINKER_CREATED);
+ if (s == NULL
+ || ! bfd_set_section_flags (dynobj, s, flags)
+ || ! bfd_set_section_alignment (dynobj, s, bed->s->log_file_align))
+ return FALSE;
+ htab->srelplt2 = s;
+ }
+
return TRUE;
}
{
flagword flags;
- sreloc = bfd_make_section (dynobj, name);
flags = (SEC_HAS_CONTENTS | SEC_READONLY
| SEC_IN_MEMORY | SEC_LINKER_CREATED);
if ((sec->flags & SEC_ALLOC) != 0)
flags |= SEC_ALLOC | SEC_LOAD;
+ sreloc = bfd_make_section_with_flags (dynobj,
+ name,
+ flags);
if (sreloc == NULL
- || ! bfd_set_section_flags (dynobj, sreloc, flags)
|| ! bfd_set_section_alignment (dynobj, sreloc, 2))
return FALSE;
}
/* We also need to make an entry in the .rel.plt section. */
htab->srelplt->size += sizeof (Elf32_External_Rel);
+
+ if (htab->is_vxworks && !info->shared)
+ {
+ /* VxWorks has a second set of relocations for each PLT entry
+ in executables. They go in a separate relocation section,
+ which is processed by the kernel loader. */
+
+ /* There are two relocations for the initial PLT entry: an
+ R_386_32 relocation for _GLOBAL_OFFSET_TABLE_ + 4 and an
+ R_386_32 relocation for _GLOBAL_OFFSET_TABLE_ + 8. */
+
+ if (h->plt.offset == PLT_ENTRY_SIZE)
+ htab->srelplt2->size += (sizeof (Elf32_External_Rel) * 2);
+
+ /* There are two extra relocations for each subsequent PLT entry:
+ an R_386_32 relocation for the GOT entry, and an R_386_32
+ relocation for the PLT entry. */
+
+ htab->srelplt2->size += (sizeof (Elf32_External_Rel) * 2);
+ }
}
else
{
else
htab->tls_ldm_got.offset = -1;
+ if (htab->is_vxworks)
+ {
+ /* Save the GOT and PLT symbols in the hash table for easy access.
+ Mark them as having relocations; they might not, but we won't
+ know for sure until we build the GOT in finish_dynamic_symbol. */
+
+ htab->hgot = elf_link_hash_lookup (elf_hash_table (info),
+ "_GLOBAL_OFFSET_TABLE_",
+ FALSE, FALSE, FALSE);
+ if (htab->hgot)
+ htab->hgot->indx = -2;
+ htab->hplt = elf_link_hash_lookup (elf_hash_table (info),
+ "_PROCEDURE_LINKAGE_TABLE_",
+ FALSE, FALSE, FALSE);
+ if (htab->hplt)
+ htab->hplt->indx = -2;
+
+ if (htab->is_vxworks && htab->hplt && htab->splt->flags & SEC_CODE)
+ htab->hplt->type = STT_FUNC;
+ }
+
/* Allocate global sym .plt and .got entries, and space for global
sym dynamic relocs. */
elf_link_hash_traverse (&htab->elf, allocate_dynrelocs, (PTR) info);
relocs = FALSE;
for (s = dynobj->sections; s != NULL; s = s->next)
{
+ bfd_boolean strip_section = TRUE;
+
if ((s->flags & SEC_LINKER_CREATED) == 0)
continue;
{
/* Strip this section if we don't need it; see the
comment below. */
+ /* We'd like to strip these sections if they aren't needed, but if
+ we've exported dynamic symbols from them we must leave them.
+ It's too late to tell BFD to get rid of the symbols. */
+
+ if (htab->hplt != NULL)
+ strip_section = FALSE;
}
else if (strncmp (bfd_get_section_name (dynobj, s), ".rel", 4) == 0)
{
- if (s->size != 0 && s != htab->srelplt)
+ if (s->size != 0 && s != htab->srelplt && s != htab->srelplt2)
relocs = TRUE;
/* We use the reloc_count field as a counter if we need
continue;
}
- if (s->size == 0)
+ if (s->size == 0 && strip_section)
{
/* If we don't need this section, strip it from the
output file. This is mostly to handle .rel.bss and
function which decides whether anything needs to go
into these sections. */
- _bfd_strip_section_from_output (info, s);
+ s->flags |= SEC_EXCLUDE;
continue;
}
/* Relocation is relative to the start of the global offset
table. */
+ /* Check to make sure it isn't a protected function symbol
+ for shared library since it may not be local when used
+ as function address. */
+ if (info->shared
+ && !info->executable
+ && h
+ && h->def_regular
+ && h->type == STT_FUNC
+ && ELF_ST_VISIBILITY (h->other) == STV_PROTECTED)
+ {
+ (*_bfd_error_handler)
+ (_("%B: relocation R_386_GOTOFF against protected function `%s' can not be used when making a shared object"),
+ input_bfd, h->root.root.string);
+ bfd_set_error (bfd_error_bad_value);
+ return FALSE;
+ }
+
/* Note that sgot is not involved in this
calculation. We always want the start of .got.plt. If we
defined _GLOBAL_OFFSET_TABLE_ in a different way, as is
+ htab->sgotplt->output_offset
+ got_offset),
htab->splt->contents + h->plt.offset + 2);
+
+ if (htab->is_vxworks)
+ {
+ int s, k, reloc_index;
+
+ /* Create the R_386_32 relocation referencing the GOT
+ for this PLT entry. */
+
+ /* S: Current slot number (zero-based). */
+ s = (h->plt.offset - PLT_ENTRY_SIZE) / PLT_ENTRY_SIZE;
+ /* K: Number of relocations for PLTResolve. */
+ if (info->shared)
+ k = PLTRESOLVE_RELOCS_SHLIB;
+ else
+ k = PLTRESOLVE_RELOCS;
+ /* Skip the PLTresolve relocations, and the relocations for
+ the other PLT slots. */
+ reloc_index = k + s * PLT_NON_JUMP_SLOT_RELOCS;
+ loc = (htab->srelplt2->contents + reloc_index
+ * sizeof (Elf32_External_Rel));
+
+ rel.r_offset = (htab->splt->output_section->vma
+ + htab->splt->output_offset
+ + h->plt.offset + 2),
+ rel.r_info = ELF32_R_INFO (htab->hgot->indx, R_386_32);
+ bfd_elf32_swap_reloc_out (output_bfd, &rel, loc);
+
+ /* Create the R_386_32 relocation referencing the beginning of
+ the PLT for this GOT entry. */
+ rel.r_offset = (htab->sgotplt->output_section->vma
+ + htab->sgotplt->output_offset
+ + got_offset);
+ rel.r_info = ELF32_R_INFO (htab->hplt->indx, R_386_32);
+ bfd_elf32_swap_reloc_out (output_bfd, &rel,
+ loc + sizeof (Elf32_External_Rel));
+ }
+
}
else
{
bfd_elf32_swap_reloc_out (output_bfd, &rel, loc);
}
- /* Mark _DYNAMIC and _GLOBAL_OFFSET_TABLE_ as absolute. */
+ /* Mark _DYNAMIC and _GLOBAL_OFFSET_TABLE_ as absolute.
+ On VxWorks, the _GLOBAL_OFFSET_TABLE_ symbol is not absolute: it
+ is relative to the ".got" section. */
if (strcmp (h->root.root.string, "_DYNAMIC") == 0
- || strcmp (h->root.root.string, "_GLOBAL_OFFSET_TABLE_") == 0)
+ || (strcmp (h->root.root.string, "_GLOBAL_OFFSET_TABLE_") == 0
+ && !htab->is_vxworks))
sym->st_shndx = SHN_ABS;
return TRUE;
if (htab->splt && htab->splt->size > 0)
{
if (info->shared)
- memcpy (htab->splt->contents,
- elf_i386_pic_plt0_entry, PLT_ENTRY_SIZE);
+ {
+ memcpy (htab->splt->contents, elf_i386_pic_plt0_entry,
+ sizeof (elf_i386_pic_plt0_entry));
+ memset (htab->splt->contents + sizeof (elf_i386_pic_plt0_entry),
+ htab->plt0_pad_byte,
+ PLT_ENTRY_SIZE - sizeof (elf_i386_pic_plt0_entry));
+ }
else
{
- memcpy (htab->splt->contents,
- elf_i386_plt0_entry, PLT_ENTRY_SIZE);
+ memcpy (htab->splt->contents, elf_i386_plt0_entry,
+ sizeof(elf_i386_plt0_entry));
+ memset (htab->splt->contents + sizeof (elf_i386_plt0_entry),
+ htab->plt0_pad_byte,
+ PLT_ENTRY_SIZE - sizeof (elf_i386_plt0_entry));
bfd_put_32 (output_bfd,
(htab->sgotplt->output_section->vma
+ htab->sgotplt->output_offset
+ htab->sgotplt->output_offset
+ 8),
htab->splt->contents + 8);
+
+ if (htab->is_vxworks)
+ {
+ Elf_Internal_Rela rel;
+ struct elf_link_hash_entry *hgot;
+
+ /* The VxWorks GOT is relocated by the dynamic linker.
+ Therefore, we must emit relocations rather than
+ simply computing the values now. */
+ hgot = elf_link_hash_lookup (elf_hash_table (info),
+ "_GLOBAL_OFFSET_TABLE_",
+ FALSE, FALSE, FALSE);
+ /* Generate a relocation for _GLOBAL_OFFSET_TABLE_ + 4.
+ On IA32 we use REL relocations so the addend goes in
+ the PLT directly. */
+ rel.r_offset = (htab->splt->output_section->vma
+ + htab->splt->output_offset
+ + 2);
+ rel.r_info = ELF32_R_INFO (hgot->indx, R_386_32);
+ bfd_elf32_swap_reloc_out (output_bfd, &rel,
+ htab->srelplt2->contents);
+ /* Generate a relocation for _GLOBAL_OFFSET_TABLE_ + 8. */
+ rel.r_offset = (htab->splt->output_section->vma
+ + htab->splt->output_offset
+ + 8);
+ rel.r_info = ELF32_R_INFO (hgot->indx, R_386_32);
+ bfd_elf32_swap_reloc_out (output_bfd, &rel,
+ htab->srelplt2->contents +
+ sizeof (Elf32_External_Rel));
+ }
}
/* UnixWare sets the entsize of .plt to 4, although that doesn't
really seem like the right value. */
elf_section_data (htab->splt->output_section)
->this_hdr.sh_entsize = 4;
+
+ /* Correct the .rel.plt.unloaded relocations. */
+ if (htab->is_vxworks && !info->shared)
+ {
+ int num_plts = (htab->splt->size / PLT_ENTRY_SIZE) - 1;
+ unsigned char *p;
+
+ p = htab->srelplt2->contents;
+ if (info->shared)
+ p += PLTRESOLVE_RELOCS_SHLIB * sizeof (Elf32_External_Rel);
+ else
+ p += PLTRESOLVE_RELOCS * sizeof (Elf32_External_Rel);
+
+ for (; num_plts; num_plts--)
+ {
+ Elf_Internal_Rela rel;
+ bfd_elf32_swap_reloc_in (output_bfd, p, &rel);
+ rel.r_info = ELF32_R_INFO (htab->hgot->indx, R_386_32);
+ bfd_elf32_swap_reloc_out (output_bfd, &rel, p);
+ p += sizeof (Elf32_External_Rel);
+
+ bfd_elf32_swap_reloc_in (output_bfd, p, &rel);
+ rel.r_info = ELF32_R_INFO (htab->hplt->indx, R_386_32);
+ bfd_elf32_swap_reloc_out (output_bfd, &rel, p);
+ p += sizeof (Elf32_External_Rel);
+ }
+ }
}
}
#define elf32_bed elf32_i386_fbsd_bed
#include "elf32-target.h"
+
+/* VxWorks support. */
+
+#undef TARGET_LITTLE_SYM
+#define TARGET_LITTLE_SYM bfd_elf32_i386_vxworks_vec
+#undef TARGET_LITTLE_NAME
+#define TARGET_LITTLE_NAME "elf32-i386-vxworks"
+
+
+/* Like elf_i386_link_hash_table_create but with tweaks for VxWorks. */
+
+static struct bfd_link_hash_table *
+elf_i386_vxworks_link_hash_table_create (bfd *abfd)
+{
+ struct bfd_link_hash_table *ret;
+ struct elf_i386_link_hash_table *htab;
+
+ ret = elf_i386_link_hash_table_create (abfd);
+ if (ret)
+ {
+ htab = (struct elf_i386_link_hash_table *) ret;
+ htab->is_vxworks = 1;
+ htab->plt0_pad_byte = 0x90;
+ }
+
+ return ret;
+}
+
+
+/* Tweak magic VxWorks symbols as they are written to the output file. */
+static bfd_boolean
+elf_i386_vxworks_link_output_symbol_hook (struct bfd_link_info *info
+ ATTRIBUTE_UNUSED,
+ const char *name,
+ Elf_Internal_Sym *sym,
+ asection *input_sec ATTRIBUTE_UNUSED,
+ struct elf_link_hash_entry *h
+ ATTRIBUTE_UNUSED)
+{
+ /* Ignore the first dummy symbol. */
+ if (!name)
+ return TRUE;
+
+ return elf_vxworks_link_output_symbol_hook (name, sym);
+}
+
+#undef elf_backend_post_process_headers
+#undef bfd_elf32_bfd_link_hash_table_create
+#define bfd_elf32_bfd_link_hash_table_create \
+ elf_i386_vxworks_link_hash_table_create
+#undef elf_backend_add_symbol_hook
+#define elf_backend_add_symbol_hook \
+ elf_vxworks_add_symbol_hook
+#undef elf_backend_link_output_symbol_hook
+#define elf_backend_link_output_symbol_hook \
+ elf_i386_vxworks_link_output_symbol_hook
+#undef elf_backend_emit_relocs
+#define elf_backend_emit_relocs elf_vxworks_emit_relocs
+#undef elf_backend_final_write_processing
+#define elf_backend_final_write_processing \
+ elf_vxworks_final_write_processing
+
+/* On VxWorks, we emit relocations against _PROCEDURE_LINKAGE_TABLE_, so
+ define it. */
+#undef elf_backend_want_plt_sym
+#define elf_backend_want_plt_sym 1
+
+#undef elf32_bed
+#define elf32_bed elf32_i386_vxworks_bed
+
+#include "elf32-target.h"
projects / deliverable / binutils-gdb.git / blobdiff